OCIO Player:
The OCIOPlayer node is a specialized viewer node designed to display image sequences or video frames within a graph, focusing on high dynamic range (HDR) content. It serves as an in-graph float viewer, allowing you to preview images in their full resolution and HDR-preserving half-float format, which is crucial for maintaining the integrity of color and exposure in visual content. Unlike other nodes, OCIOPlayer is input-only and does not produce any outputs, ensuring that it functions purely as a viewer without affecting the data flow in the graph. This design prevents potential issues such as endless refresh loops or data routing errors. The node caches incoming frames to a temporary directory, capped at a maximum of 240 frames, to manage memory usage efficiently while still providing a seamless viewing experience. This makes OCIOPlayer an essential tool for artists who need to verify the visual quality of their work directly within the node graph.
OCIO Player Input Parameters:
images
This parameter accepts any image batch, whether it's a single still image (N=1), a sequence, or a video (N>1). It allows you to input a variety of visual content for previewing within the node. The images are processed in their full resolution and HDR-preserving format, ensuring that the viewer displays them accurately. There are no specific minimum or maximum values, as this parameter is designed to handle a wide range of image inputs.
video
The video parameter is used to connect a Load Video node, enabling the streaming of a movie directly in the viewport. This feature leverages WebCodecs for decode-on-demand, meaning the entire clip does not need to be materialized, which can save on processing resources. When both images and video are connected, the video takes priority for display in the viewer. This parameter is particularly useful for previewing video content without the need for full materialization.
alpha
This optional parameter allows you to input an alpha mask to view or carry through with the images. The alpha channel can be used to manage transparency or other masking effects in the visual content. If no alpha is provided, a default mask of ones is used, ensuring that the images are displayed without transparency by default.
base
The base parameter is a string that represents the source first-frame number, set by the front end from the upstream OCIO Read node. It is used to adjust the frame indices to be 0-based, which is necessary for accurate batch processing. The default value is "0", indicating that the indices are already 0-based. This parameter ensures that the frame numbering aligns correctly with the source material.
OCIO Player Output Parameters:
(No output parameters)
OCIOPlayer does not produce any output parameters. It is designed solely as a viewer node, meaning it only takes inputs for display purposes and does not pass any data through or generate outputs. This design choice helps maintain the integrity of the node graph by preventing unintended data routing through the viewer.
OCIO Player Usage Tips:
- To optimize performance, ensure that the number of frames being previewed does not exceed the frame cap of 240, as this can help manage memory usage effectively.
- When working with video content, connect a Load Video node to the video input to take advantage of the streaming capabilities, which can reduce the need for full materialization and improve processing efficiency.
- Use the alpha parameter to preview transparency effects or masks, which can be crucial for compositing tasks or when working with layered content.
OCIO Player Common Errors and Solutions:
"Nothing connected -> empty viewer"
- Explanation: This error occurs when no images or video are connected to the OCIOPlayer node, resulting in an empty viewer.
- Solution: Ensure that either the images or video input is connected with valid content to display in the viewer.
"Stuck on frame 1, endless Refresh"
- Explanation: This issue arises when the output of the OCIOPlayer is mistakenly wired back into the graph, causing a loop.
- Solution: Remove any connections from the OCIOPlayer's output, as it is an input-only node and should not be used to route data through the graph.